'Reward' in the Bible

Now may the Lord reward you with gracious love, as well as faithfulness, to you, too! And I will also reward you because you did this good thing.

when the man who told me "Look! Saul is dead!' thought he was bringing me good news, I arrested him and had him killed at Ziklag as the reward I gave him for his news.

"Please," Zadok's son Ahimaaz continued, "No matter what happens, let me follow the Ethiopian!" Joab asked him, "Why this request to run, my son? There's no reward in it for you."

Your servant will cross the Jordan River with the king for a short distance, but why should the king offer me this reward?